Micro-projector



R. P. PORTER MICRO-PROJECTOR Oct. 15, 1935.

Filed Jan. 9, 1935 2 Sheets-Sheet l Oct. 15, 1935, R. P. PORTER MICRO-PROJECTOR F-iled Jan. 9, .1935 2 Sheets-Sheet 2 LA; :wmm

Patented Oct. 15 1935 UNITED STATES PATENT OFFICE ivncno-rnomc'ron Ray P. Porter, Abilene, Tex. Application January 9, 1933, Serial No. 650,815 v W Claims. v(c1. 8824) This invention relates to an improved illuminated micro-projector and seeks, among other objects, to provide a device of this character which will, with a. small light source, effectually project 5 the image of a specimen so that it may be .readily observed by several persons at one time.

Another object of the invention is to provide an illuminated micro-projector wherein lenses are employed which will permit the disposing of the 10 specimen near the light source and which will magnify the light beams in such a manner that the image of the specimen will be clearly shown within a dark box disposed below the lenses.

' Another object of the invention is to provide an illuminated micro-projector which is adapted to be adjustably carried on a stand and wherein the lenses and light source employed are adjustable with respect to the specimen stage so that the lenses may be focused for clearly projecting specimens of different types.

' Another object of the invention is to provide a micro-projector employing a light source of great simplicity and flexibility.

A further object of the invention is to provide an illuminated micro-projector which is characterized by the utmost simplicity and'compactness and which may be produced cheaply and on a large scale so that a class could be provided with individual instruments if desired.

And a still further object of the invention is to provide a micro-projector employing a light source which will be so disposed that heating of the specimen will not occur.

Other and incidental objects of the invention,

not particularly mentioned in the foregoing, will be apparent during the course of the following description.

In the accompanying drawings forming a part of this application,

4 Y Figure 1 is a perspective view of the device in operative position,

Figure 2 is an enlarged fragmentary vertical sectional view of the device,

Figure 3, is an enlarged fragmentary horizontal sectional view on the line 33 of Figure 2, looking in the direction indicated by the arrows,

Figure 4 is an enlarged vertical sectional view of the dark box employed, and

Figure 5 is an enlarged fragmentary vertical 0 sectional view showing a slightly modified form of illuminator.

Referring now to the accompanying drawings, the numeral l indicates an upright stand which is similar in construction to the usual ring stands 5 commonly used in laboratories for supporting different implements used in experimental work.

Associated with the stand is a straight supporting arm 2 which is externally threaded at its outer end and is provided with a double laboratory clamp 3 which is slidable on the stand I. Screwed through the wall of the clamp 3 is a locking screw 4 which is adapted for locking theclamp and arm in a desired adjusted position on the stand.-

Associated with the arm 2 is a stage 5 which is preferably formed of lightweight metalandis 13 square in shape. As best seen in Figure 3 of the drawings; the externally threaded outer end portion of the arm 2 is screwed into a side wall of the stage, medially thereof, and formed in the stage 5, centrally thereof, is an opening 6. Normally 15 overlying the opening is a removable object or specimen slide 1. Mounted on the stage 5, near one edge thereof, are spaced posts 8, and carried on said posts are spring fingers 9 which normaliy engage the slide 1 and retain it in a fixed position 20 over the opening;

Upstanding from the stage 5, at one corner thereof and near one of the posts 8, is an adjustable bracket supporting rod l0, and carried, by said rodjat its upper end, is a flat metal brack- 5 et 1 l which extends horizontally in parallel spaced relation to the stage thereabove. The bracket is widened towards its free end. Formed in the stage 5, near the rod I0, is a socket I2 and carried in the socket is alocking sleeve l3 whichis 30 reduced and threaded at its outer end. Screwed on the threaded outer end of the sleeve I3 is a locking nut l4. As best seen in Figure 3 of the drawings, the socket I2' communicates with the opening through which the'rod I0 passes and the 35 sleeve 13 is notched to receive the rod so that, when the locking nut I4 is rotated, the sleeve 13 is shifted outwardly for wedging the rod in locked position. It will be seen that the rod l0 may thus be locked in any desired position. v 40 Carried on the bracket I l at its enlarged outer end is the illuminator. The illuminator comprises a tubular sleeve l5 which extends through the enlarged outer end portion of the bracketll axially thereof. The major portion of the 5 tubular sleeve l5 extends above the bracket H and a small portion thereof extends below said bracket. Carried on the upper face of the bracket H, in concentric spaced relation to the tubular sleeve I5, is a threaded socket l6 which is adapted to receive the lower end portion of. a conventional fiash light barrel in a manner to be hereinafter described. Slidably fitted about the tubular sleeve 15 is a tubular housing H which is closed at its upper 'end by an end wall l8 close spaced relation preferably formed of insulating material. The

housing isadapted to slide vertically upon the sleeve l5 and is rotatable thereabout for permitting adjustment, 'as will be hereinafter described'in more detail. The end wall I8 is held in place by punching the upper rib of the .wall of the housing inwardly into contact with the edge of the wall 18. Formed in the wall of the housing I! is an opening l9 and formed in the wall I8 are spaced openings 20 for providing ventilation for the interior of the housing. Mounted concentrically within the housing l1, near its upper end, is a socket 2| which may be of' the well-known bayonet type. place by set screws 22,. preferably three in number, which are screwed through the wall of the housing I! at equally spaced points thereon. Carried on the-end wall [8 is a binding post 23 which is preferably electrically connected with the center terminal of the socket 2|. A second binding post 24 is carried on the end wall l8 and is electrically connected with the rim terminal of. the socket 2|. Carried in the socket 2| is a bulb 25.

The binding posts are preferably electrically connected with a current source through a suitable switch so that the current to the bulb may be readily controlled. It should be understood that the screws 22 permit adjustment of the socket and bulb within the housing l1.

Snugly but slidably fitted within the tubular sleeve I5 is a condenser assembly which-comprises, respectively, slidable inner and outer sleeves 26 and 21. The sleeve 26 is internally threaded at its lower end and screwed into said sleeve is a relatively large condenser lens 28. The sleeve 21 is provided with an enlarged portion 29 defining a shoulder 30 against which the upper end of the sleeve26 abuts. The portion 29 is internally threaded and screwed therein is a rim 3| carrying a relatively small condenser lens 32. It is to be noted that the lens 28 is g of substantially twice the diameter of the lens 32. The lens 32 should be of relatively short focal distance so that it may be disposed in relatively to the bulb 25. The condenser lens 28 is so disposed that'it will permit the placing of the bulb 25 near' the lens 32 so that the transmitted divergent rays will be collected and converged upon the specimen, as will be more fully described hereinafter. It should be understood that the condenser lenses may be adjusted with respect to each other by simply sliding the inner sleeve 26' within the outer sleeve 21. A more coarse adjustment may be obtained by sliding the entire cfiidenser assembly within the tubular sleeve l5 and, of course, further adjustment may be accomplished by sliding the housing I! upon the sleeve l5.

4 Mounted at a corner of the stage 5, substantially in alinement with the posts 8 and the rod I0, is a depending adjustable supporting rod 33 and associated with the rod 33 at its lower end is an objective supporting bracket 34. Associated with the rod 33 is a locking sleeve 35 and a looking screw 36, the sleeve and screw 35 and 36 operating in a manner identical with the sleeve l3 and screw l4 previously described. As best seen in Figure 1, the objective supporting bracket 34 is preferably formed of fiat metal and extends diagonally at' right angles to the bracket l I in horizontal spaced relation below the stage 5. Carried on the bracket 34, at its outer end, is an adjustable objective 3'! which is preferably screwed into said bracket. Carried within the objective The socket is held in 31 are objective lenses 38 which are adjustable within the casing for varying the focus of. light projected from the condenser lenses 28 and 32 through the specimen on the slide 1. The rod 33 is, of course, adjustable, as previously stated, for giving a coarse adjustment whereas the objective is adjustable for giving a very fine adjustment. The same condition applies to the rod l0 which may be coarsely adjusted and the condenser lens 28 which may be adjusted to a very fine point for projecting the desired light through the specimen.

Associated with the stage and lenses is a preferabl'y square dark box'39 and formed on the box 39, substantially medially of the top wall thereof, is a preferably frusto-conical sight tube amount of 40 which is normally disposed beneath the objective casing. Formed in the top wall of the box, near one side thereof, is a preferably triangular sight opening 4|. As best seen in Figure 4 of the drawings, the dark box 39 is provided with a swinging front wall 42 which is hingedly connected to the box by means of hinges 43, the front wall 42 being raised when it is desired to insert the hand and remove'or' change the position of a drawing carried within the box.

In use, after a specimen slide containing a specimen to beobserved has been placed over the opening 6, the bulb is illuminated. The student or professor desiring to observe the specimen then adjusts the position of the condenser lenses and the objective lenses so that the beam of light from the bulb will be directed through the specimen and into the dark box, wherein the image of the specimen will be clearly shown upon a sheet of paper or the like so that a drawing may be made of the specimen if desired. Attention is particularlydirected to the fact that, inasmuch as a small condenser lens with a very short focal distance is employed, together with a second condenser lens, the small condenser lens may be placed very near the bulb so that-the bulb will be disposed inside the focal point whereby the collection of the transmitted divergent rays may be converged'to project through the specimen to Y the objective lens. In this manner, it is possible to get sufficient illumination from a small flash light bulb to serve the purpose of micro-projection. This construction is particularly advantageous for the reason, that it is possible to provide a very simple and compact lightweight micro-projector which may be readily adjusted.

Attention is further directed to the fact that heating of the specimen, which is sometimes caused by disposing the specimen too close to the light source, will 'be prevented in the present device for the reason that the condenser lenses permit the focusing of the light rays in such a manner that while the light source is disposed in distal relation to the specimen, diminishing of the light is not caused. It is pointed out that the light source is so small that heat caused by said light source will not be present to any' appreciable extent, in any event.

Attention is further directed to the fact that, in view of the extreme simplicity of the device and the small number of working parts, it is possible to produce the device on a large scale so that individual instruments may be. furnished members of a class at a small cost. The simplicity in construction, coupled with the'readv adjustability of the various parts, permits the condenser and objective lenses'to be quickly adjusted with respect to the specimen so that a number of specimens may be observed in quick aoraaca is mounted a sleeve d which is of like construction to the sleeve 15. Mounted in the sleeve d5 are the condenser lenses Mi which are similar to the lenses 28 and 32 of the preferred form. Mounted on the upper face of the bracket 44 is a socket M having an upstanding internally threaded flange 48, which socket is similar in construction to the socket l6. Screwed into the flange 68 is a tubular flash light barrel t9 which may be of any standard construction and. is

bulb 50 which is disposed above the condenser lenses 46' in relatively close spaced relation thereto. The barrel 49 will, of course, carry the usual flash light batteries and will also be provided with a switch of conventional construction so that the bulb may be illuminated when desired. Aside from the aboveadapted to carry a discussed modified construction of the illuminator, the invention will function in a like manner to the preferred form in every respect.

It should be further noted that, if desired, the arm 2 may be rotated axially in the clamp 3 to a horizontal position for projecting the image against a vertical surface instead of a horizontal surface, as shown in the drawings.

It is to be understood that the lenses employed may be of any well-known commercial variety and maybe bought separately and installed in the sleeves, if desired. It is to be further understood that the objective may be of a standard type, if desired.

It is, of course, obvious that the dark box described may be substituted by another type of dark box, or may be eliminated entirely, at the option of the operator.

It is believed that I have provided a simple, compact and lightweight micro-projector which may be utilized with the utmost facility in experimental and other work.

Having thus described the invention, I claim:

1. A micro-projector including a stage, mounting means therefor, a specimen slide carried on the stage, a condenser mounted above the stage, an objective mounted beneath the stage, illuminating means mounted above the condenser, and a dark box mounted beneath the objective and having a sight opening and a hinged front wall, said illuminating means cooperating with the condenser and objective for projecting the image of the specimen on the slide into the dark box and said hinged front wall being adapted to permit insertion of the hands whereby tracing of the image seen through the sight opening may be efiected.

2. A micro-projector including a stage, adjustable mounting means therefor, a condenser mounted above the stage and supported thereby, illuminating means mounted above the condenser, an objective mounted below the stage, and a. dark box mounted below the objective, said stage, condenser and objective being adjustable to different heights above the dark box and said illuminating means cooperating with the condenser and. the objective for projecting the image of a specimen carried on the stage into the dark box.

3. A micro-projector including a stage, supporting means therefor, a rod carried at one end of the stage, a bracket carried by the rod above the stage, a sleeve carried by the bracket, inner illuminator and the stage, and a specimen slide and outer sleeves carried within said first-'mentioned sleeve, condenser lenses slidably mounted within the inner and outer sleeves, said inner and outer sleeves being slidable with respect to. each other, illuminating means mounted above the 5 condenser lenses, an objective carried below the stage, and means for adjusting the objective below the stage, said objective, condenser lenses and illuminating means cooperating for projecting the image of a specimen on the stage to a point below the objective.

4. A micro-projector including a stage, supporting means therefor, a rod carried at one corner of the stage, a bracket carried by the rod above the stage, condenser lenses carried by the bracket, illuminating means carried by the bracket above the condenser-lenses, a second rod carried by the stage at another corner thereof, and an objective carried by said second rod beneath the stage and cooperating with the condenser lenses 20 andthe illuminating means for projecting the image of a specimen carried'on the stage to a point beneath the objective.

5. A micro-projector including a stage, a supporting arm carried thereby, a stand associated 25 with the arm, condenser lenses carried above the stage, mounting means for said lenses, illuminating means carried by said mounting means -above said lenses, an objective carried below the stage, and a dark box mounted below the objective in 30 spaced relation thereto, said objective, condenser lenses and illuminating means cooperating to project the image of a specimen carried on the stage to a point within the dark box.

6. A micro-projector including a stage, a speci- 35 men slide carried thereon, condenser lenses mounted above the stage, an objective mounted below the stage, illuminating means mounted above the condenser lenses, and a dark box mounted below the objective and provided with a 40 frusto-conical sight tube,'the condenser lenses, illuminating means and objective being adjustable with respect to each other and to the dark box and cooperating to project the image of a specimen on the slide into the dark box through 45 the sight tube.

'7. A micro-projector including a stage, a rod carried at one corner thereof, an objective supporting bracket carried by the rod below the stage, an objective adjustable in said bracket and including a pair of objective lenses, condenser lenses mounted above the stage, an illuminator mounted above the condenser lenses, said condenser lenses being adjustable with respect to the 55 carried on the stage, said condenser lenses, illuminator and adjustable objective cooperating to permit the projection of the image of the specimen carried on the slide to a point below the objective.

8. A micro-projector including a stage, a rod carried at one corner thereof, a bracket carried by the rod above the stage, a sleeve carried by the bracket, an outer sleeve slidable within the bracket and having a relatively small condenser lens, an inner sleeve carried within said outer sleeve and having a relatively large condenser lens, said inner and outer sleeves being slidable with respect to each other for varying the focus of the lenses, an illuminator carried by the bracket about said first-mentioned sleeve and comprising a housing and a socket and bulb within the housing, and an objective carried below the stage and cooperating with the condenser lenses and illuminator for projecting the image of a specimen carriedon the stage to a point beneath the objective.

9. A micro-projector including a stage, an objective below the stage, condenser lenses above the stage, a bracket above the. stage, condenser lenses carried by the bracket, av housing removably carried by the bracket above the lenses and having an opening, an insulating wall closing the upper end of the housing, terminals carried on said wall for connection to a. current source, a socket within the housing, means concentrically mounting the socket within the housing, and a bulb carried in the socket and energizable by the current source, the bulb cooperating with the lenses and objective for projecting the image of a specimen on the stage to a point below the objective.

10. A micro-projector including a stage, supporting means therefor, a condenser mounted above the stage and supported thereby, an objective mounted below the stage and supported thereby, illuminating means carried above the condenser, and a dark box carried beneath the objective, said illuminating means, said condenser and objective being independently movable with respect to each other and the dark box and cooperating for projecting the image of a specimen on the stage into the dark box.

RAY P. PORTER. 

